Generally, existing flat panel display device includes an array substrate for controlling pixel display by controlling on/off of each pixel through thin-film transistors distributed over every pixel region in the meantime, as to TN mode liquid crystal display products, the array substrate further includes a common electrode line (COM) for providing a common reference voltage for pixel display. As shown in FIG. 1, the common electrode line 4 in existing TN mode array substrate has a fork shape, and includes a portion parallel to a gate line and a portion extending downward along a data line direction. A total resistance of the common electrode line 4 is great, which reduces an overall uniformity of the common electrode voltage Vcom. Besides, the common electrode line does not have a function for repairing disconnection of the data line, which cannot provide advantageous effects for improving the yield of the array substrate.